Question: Add. $1.9 + 2 =$
There are many ways to solve this problem. Let's see two ways we can solve it. Place value table Let's line up the numbers by their decimal places. Ones $.$ Tenths ${1}$ $.$ ${9}$ $2$ $.$ ${0}$ Because $2$ is a whole number, we can add a decimal point and a $0$ behind to make the columns align. Now, let's add each place value column. Ones $.$ Tenths ${1}$ $.$ ${9}$ $+$ ${2}$ $.$ ${0}$ $\underline{~~~~}$ $\underline{~~~~}$ $\underline{~~~~}$ $3$ $.$ $9$ Decomposing the numbers We can group the whole numbers together and the decimals together. $\begin{aligned} &(1 + 2) + {0.9}\\\\ &=3 + {0.9}\\\\ &=3.9 \end{aligned}$ $1.9 + 2=3.9$